NUMERICAL INVESTIGATIONS OF A SPENT FUEL STORAGE POOL IN ABNORMAL CONDITIONS

摘要

This paper deals with the thermal behavior of spent fuel storage pools, in the situations of loss and restart of the forced cooling system. The objective is to set up methodologies for the modeling of the two phase flow behavior. A first approach is performed with a single phase code (Code_Saturne). A simplified boiling model is then implemented considering flashing below the free surface. An agreement with in situ measurements is obtained for the natural convection flow occurring in normal conditions and in the first hours after the loss of cooling. In a second step a more detailed multiphase modeling is set up, thanks to the Neptune_CFD code. The boiling inside the pool and the heat and mass transfers at the free surface are simultaneously calculated. The early times computed are analyzed and compared positively with the single phase simplified model. Finally, further steps are described.